The nursery, commercial greenhouse and truck farming industries commonly use pots for growing small plants to be sold to home owners, gardeners, etc. Typically, several empty pots are closely arrayed in a shallow tray called a "flat"; the pots are filled with a mixture of soil, fertilizer, etc.; and a seed or seedling is planted in each pot. The flat of pots is then cultivated as a group for the entire grow-in period. If it becomes necessary to move the pots, the entire flat is carried with the pots remaining in their individual pockets or "cells" within the flat.
Since commercial operations go through a large number of pots and flats, they are usually delivered and stored in large stacks. It is thus highly desirable that the pots and even the flats "nest" together; i.e., the pots fit together in a stack to minimize the dead space therebetween, and likewise for the flats, to render the stacks as compact as possible.
In addition to being nestable, it is important for the pots and flat to work together to form an efficient flat/pot containing system. An efficient system can have several advantageous features. For example, a flat/pot system can be designed in such a way that the flat holds the pots snugly together, thereby minimizing gaps between the pots and the leakage of soil, water, etc. therebetween. Also, a flat can, and typically does, permit water to freely drain from the pots. And a well designed flat is usually strong enough to permit an entire array of filled pots to be carried as a group.
A particularly desirable feature of a flat/pot containing system, and one that is the subject of one aspect of the present invention, is for the flat to frictionally grip the sides of the pots. This prevents the pots from falling over or moving about as the flat is being moved, noting that in some cases the flat will not be completely filled with pots so stability cannot be assured by tightly packing the pots within the flat.
While it is desirable for the flat to frictionally grip the pots, this feature can potentially interfere with the filling of the flat's pockets or cells with the pots. That is, if the flat grips the pots too tightly it may be unnecessarily difficult to insert the pots into the flat's pockets or cells. Also, Applicants have found that unless the flat grips the pots just right, the flat can tend to grip not only the bottom/outer pot of a stack of pots, but also one or more of the upper/inner pots. This can delay the cell filling process, which for some commercial operations involves moving a stack of nested pots from cell to cell to populate all of the cells with empty pots. But if more than one pot is frictionally retained within a given cell, the operator has to delay the normal cell filling process to retrieve the surplus pot(s) from that cell; or alternatively continue with the cell filling process in spite of the fact that some of the cells may contain multiple pots. For a commercial operation, either alternative is wasteful and costly. This scenario would apply whether the flat filling operation is done manually or with the assistance of a machine.
The present invention is directed to a flat and a flat/pot system that possess one or more of the desired characteristics set forth above, and address the problems associated with the prior art flats and flat/pot systems.